We all know we need iron to live.
众所周知，铁是我们不可或缺的微量元素。
How else would our bloodcarry oxygen to our lungs?
如果不是通过铁元素，我们的血液怎么能把氧气送入肺部呢？
And cells need iron in order tomultiply.
细胞分裂也需要铁元素的协助。
The problem is that our cells aren't the only ones whoneed iron in order to thrive.
但问题是，不仅正常细胞需要铁元素帮助繁殖。
Cancer cells and harmful microorganisms like E.Coli and staph neediron, too.
癌细胞的分裂以及像大肠杆菌和葡萄球菌这样的有害微生物的滋生也需要铁元素。
The good news is that our bodies have several mechanisms for preventing dangerous invadersfrom getting the iron they need.
幸运的是，我们人体内有一些防御机制可以抵御有害入侵者，防止他们获取所需的铁元素。
Our bodies' defense strategy is to starve these invaders andcontain them.
我们人体对入侵者采取的防御战略是：断其粮草、形成牵制。
First, the level of iron in our blood plasma drops down dramatically, and our bodies reduce theamount of iron we absorb from our diet to a bare minimum until the danger is over.
首先，我们血浆中的铁含量会急剧下降，同时我们的身体会尽量减少饮食中对铁的吸收，直到危险解除。
Next, ourwhite blood cells have a protein that scavenges for loose iron atoms so that the invaders don't geta hold of them.
接下来，我们白血球中所含的一种蛋白质会清理游离的铁原子，这样入侵者就无法得到铁。
Finally, to seal the deal, our immune system forms antibodies to the proteinreceptors the invaders use to acquire iron.
最后，为永绝后患，我们的免疫系统对入侵者用来捕获铁元素的蛋白受体形成抗体。
The next time the same organism invades, the seantibodies will completely block it from getting the iron it needs.
当微生物再次入侵时，它将会被这些抗体彻底阻挡在外，从而无法获取所需的铁。
No wonder, then, that having too much iron in your system can mean the difference between life and death.
另外，我们也不难理解为什么人体内铁元素过量将事关生死。
Too much iron clogs our bodies' natural debris-control system and suppresses ourwhite blood cells.
大量的铁元素会使人体自身对自由基的控制受阻并抑制白血球生长繁殖。
What's more, iron is a powerful oxidant, so when iron reacts with oxygen,it can damage the DNA in our cells and actually trigger the cancer process.
此外，铁具有强氧化性，因此当其与氧气发生反应时，可以破坏细胞中的DNA，从而引发癌变。
Help your body protect you by making sure that you're not consuming too much iron.
确保不要过量摄入铁元素有助于你的机体对你形成保护。
Avoid ironsupplements unless your doctor prescribes them, and stop smoking. Tobacco is loaded with iron.
在未经医嘱的情况下，尽量不要补铁，并且要戒烟，因为烟草中富含铁元素。
